The present invention related generally to steel beams and, more particularly, to a modular steel beam that can be assembled in place.
Trends in residential building call for large, open spaces and high ceilings, creating a demand for structural members that provide higher strength and greater stability over longer spans than conventional lumber. Engineered lumber, such as wood I-beams, laminated veneer lumber (LVL), and glulam beams, are often used in place of conventional lumber in residential designs where high loads and/or long spans are present. Engineered lumber, however, is more expensive than conventional lumber and, therefore, increases the cost of construction. Also, engineered lumber is frequently custom-designed for a particular application, creating a logistical problem for the builder, who must coordinate the design, manufacture, and transportation of the engineered lumber to the work site.
Structural steel, such as steel trusses and I-beams, provide another alternative to conventional lumber in residential designs where high loads and/or long spans are present. Steel members are relatively inexpensive and come in a wide variety of sizes and shapes which are readily available. However, large steel members can be difficult to handle due to their size and weight. Oftentimes, special equipment such as cranes or other lifting equipment is needed to put steel members in place.
Accordingly, there is still a need for structural members for residential construction that provide greater strength and stability over long spans than conventional lumber, yet are relatively inexpensive, readily available, and easily handled on the work site.
The present invention is a modular steel I-beam that can be assembled in place at a construction site. In one embodiment, the modular I-beam comprises a plurality of nested steel channels fastened to a central beam made of wood to form an I-beam. The builder chooses the size and number of steel channels to fasten to the central beam depending upon the requirements of a particular application. The steel channels may be combined in a variety of ways, allowing the builder to effectively build a custom designed I-beam for a given application.
In one exemplary embodiment of the invention, the nested channels are provided in paired sets. Each paired set comprises an outer channel and an inner channel. The outer and inner channels each comprise two flanges connected by a central web. The outer ends of the flanges are angled inwardly toward a midline of the channel. In the preferred embodiment, the flanges of the inner channel angle outwardly such that the flanges of the inner channel bear against the flanges of the outer channel. This arrangement makes the inner channel self-aligning with respect to the outer channel and facilitates assembly at the construction site. The inner channel effectively snaps into the outer channel and the angle on the outer end of the flanges for the outer channel helps retain the inner channel in a nested position.
An I-beam may be constructed by arranging two paired channels on each side of a central beam. Additional paired channels can then be nested inside the first set of paired channels. The nesting of paired channels may continue until a beam with the desired strength characteristics is formed.